Function
Protection of circuits against short-circuit currents,
Protection of circuits against overload currents,
Switch,
Isolation,
Circuit-breakers are used in domestic installation, as well as in commercial and industry electrical distribution systems.
Selection
Technical data of the network at the point considered:
the earthing systems (TNS, TNC),
Short-circuit current at the circuit-breaker installation point, which must always be less than the breaking capacity of this device,
Network normal voltage.
Tripping curves:
B curve (3-5In) protection for people and big length cables in TN and IT systems.
C curve (5-10In) protection for resistive and inductive loads with low inrush current.
D curve(10-14In) protection for circuits which supply loads with high inrush (LV/LV transformers, breakdown lamps).